(a) Field of the Invention
The present invention relates to an automatic meter reading technique and, in particular, to a system and method for measuring commodity utilization and transmitting the measurement to a remote control center over a telephony network.
(b) Description of the Related Art
Typically, utility companies have used meter reading personnel to visually read the consumed commodity information provided by utility meters and manually record the information. In recent years, however, there have been efforts to deploy fully Automatic Meter Reading Systems (AMRS).
Most AMRS systems are comprised of a utility meter, an end device attached to the utility meter for reading the commodity utilization, and a remotely located service management center, such that the end device communicates data with the remote control center over wireless communication link.
FIG. 1 is a schematic block diagram illustrating a conventional automatic meter reading system. In FIG. 1, the automatic meter reading system includes an end device 72 attached to a utility meter (not shown) and a remote control center 70 communicating with the end device such that the end device 72 reads commodity usage, such as electricity, gas, and etc., measured the utility meter and sends the measurement to the remote control center 70 under control of the remote control center 70. The end device 72 includes a detector 74 attached to the utility meter for indicating the meter reading, a memory 75 for storing data from the detector 74, a radio frequency (RF) module 71 for communicating the data with the remote control center 70, and a micro control unit 73 cooperatively controlling the above parts. The data encoded by the detector 74 based on the value measured by the utility meter are stored in the memory 75 and then transmitted to the remote management center 70 after processed at the RF module 71 under control of the MCU 73.
In the above structured conventional automatic meter reading system, if it is required to determine subscriber's consumption of the utility, the remote management center 70 broadcasts an inspection request signal containing at least one end device ID. All the end devices located in coverage of the remote management center 70 receive the inspection request signal. The inspection request signal is processed by the RF module 71 and then transferred to the MCU 73 such that the MCU 73 checks the end device ID contained in the inspection and controls the detector 74 so as to read commodity utilization measured by the utility meter if the end device ID is identical with the ID previously stored in the memory 75. The detector 74 reads the commodity utilization from the utility meter and then store the measurement data in the memory 75. Sequentially, the RF module 71 processes and transmits the measurement data to the remote control center 70 under control of the MCU 73.
Accordingly, the remote control center 70 issues a billing statement for the subscriber based on the measurement data received from the target end device 72.
However, the conventional automatic meter reading system has drawbacks in that the large investments are required for implementing wireless meter reading system in infrastructure and the wireless system are not useful for servicing customers who are widely separated because the communication range of the RF module is limited. Even tough the wires automatic meter reading system is implemented; it is unlikely to expect reliable data transmission because of the attenuation characteristics of the RF.